<?php
namespace AIOSEO\Plugin\Common\Utils;

// Exit if accessed directly.
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

use WP_Error;

/** \WP_Upgrader class */
require_once ABSPATH . 'wp-admin/includes/class-wp-upgrader.php';

/** \Plugin_Upgrader class */
require_once ABSPATH . 'wp-admin/includes/class-plugin-upgrader.php';

/**
 * In WP 5.3 a PHP 5.6 splat operator (...$args) was added to \WP_Upgrader_Skin::feedback().
 * We need to remove all calls to *Skin::feedback() method, as we can't override it in own Skins
 * without breaking support for PHP 5.3-5.5.
 *
 * @internal Please do not use this class outside of core AIOSEO development. May be removed at any time.
 *
 * @since 1.5.6.1
 */
class PluginUpgraderSilentAjax extends \Plugin_Upgrader {
	/**
	 * An array of links to install the plugins from.
	 *
	 * @since 4.0.0
	 *
	 * @var array
	 */
	public $pluginLinks = [
		'optinMonster'         => 'https://downloads.wordpress.org/plugin/optinmonster.zip',
		'wpForms'              => 'https://downloads.wordpress.org/plugin/wpforms-lite.zip',
		'miLite'               => 'https://downloads.wordpress.org/plugin/google-analytics-for-wordpress.zip',
		'emLite'               => 'https://downloads.wordpress.org/plugin/google-analytics-dashboard-for-wp.zip',
		'wpMail'               => 'https://downloads.wordpress.org/plugin/wp-mail-smtp.zip',
		'rafflePress'          => 'https://downloads.wordpress.org/plugin/rafflepress.zip',
		'seedProd'             => 'https://downloads.wordpress.org/plugin/coming-soon.zip',
		'trustPulse'           => 'https://downloads.wordpress.org/plugin/trustpulse-api.zip',
		'instagramFeed'        => 'https://downloads.wordpress.org/plugin/instagram-feed.zip',
		'facebookFeed'         => 'https://downloads.wordpress.org/plugin/custom-facebook-feed.zip',
		'twitterFeed'          => 'https://downloads.wordpress.org/plugin/custom-twitter-feeds.zip',
		'youTubeFeed'          => 'https://downloads.wordpress.org/plugin/feeds-for-youtube.zip',
		'pushEngage'           => 'https://downloads.wordpress.org/plugins/pushengage.zip',
		'sugarCalendar'        => 'https://downloads.wordpress.org/plugins/sugar-calendar-lite.zip',
		'wpSimplePay'          => 'https://downloads.wordpress.org/plugins/stripe.zip',
		'easyDigitalDownloads' => 'https://downloads.wordpress.org/plugins/easy-digital-downloads.zip',
		'searchWp'             => '',
		'affiliateWp'          => ''
	];

	/**
	 * An array of links to install the plugins from wordpress.org.
	 *
	 * @since 4.0.0
	 *
	 * @var array
	 */
	public $wpPluginLinks = [
		'optinMonster'  => 'https://wordpress.org/plugin/optinmonster/',
		'wpForms'       => 'https://wordpress.org/plugin/wpforms-lite/',
		'miLite'        => 'https://wordpress.org/plugin/google-analytics-for-wordpress/',
		'emLite'        => 'https://wordpress.org/plugin/google-analytics-dashboard-for-wp/',
		'wpMail'        => 'https://wordpress.org/plugin/wp-mail-smtp/',
		'rafflePress'   => 'https://wordpress.org/plugin/rafflepress/',
		'seedProd'      => 'https://wordpress.org/plugin/coming-soon/',
		'trustPulse'    => 'https://wordpress.org/plugin/trustpulse-api/',
		'instagramFeed' => 'https://wordpress.org/plugin/instagram-feed/',
		'facebookFeed'  => 'https://wordpress.org/plugin/custom-facebook-feed/',
		'twitterFeed'   => 'https://wordpress.org/plugin/custom-twitter-feeds/',
		'youTubeFeed'   => 'https://wordpress.org/plugin/feeds-for-youtube/',
		'pushEngage'    => 'https://wordpress.org/plugins/pushengage/',
		'sugarCalendar' => 'https://wordpress.org/plugins/sugar-calendar-lite/',
		'wpSimplePay'   => 'https://wordpress.org/plugins/stripe/',
		'searchWp'      => 'https://searchwp.com/',
		'affiliateWp'   => 'https://affiliatewp.com/'
	];

	/**
	 * An array of slugs to check if plugins are activated.
	 *
	 * @since 4.0.0
	 *
	 * @var array
	 */
	public $pluginSlugs = [
		'optinMonster'         => 'optinmonster/optin-monster-wp-api.php',
		'wpForms'              => 'wpforms-lite/wpforms.php',
		'wpFormsPro'           => 'wpforms/wpforms.php',
		'miLite'               => 'google-analytics-for-wordpress/googleanalytics.php',
		'miPro'                => 'google-analytics-premium/googleanalytics-premium.php',
		'emLite'               => 'google-analytics-dashboard-for-wp/gadwp.php',
		'emPro'                => 'exactmetrics-premium/exactmetrics-premium.php',
		'wpMail'               => 'wp-mail-smtp/wp_mail_smtp.php',
		'wpMailPro'            => 'wp-mail-smtp-pro/wp_mail_smtp.php',
		'rafflePress'          => 'rafflepress/rafflepress.php',
		'rafflePressPro'       => 'rafflepress-pro/rafflepress-pro.php',
		'seedProd'             => 'coming-soon/coming-soon.php',
		'seedProdPro'          => 'seedprod-coming-soon-pro-5/seedprod-coming-soon-pro-5.php',
		'trustPulse'           => 'trustpulse-api/trustpulse.php',
		'instagramFeed'        => 'instagram-feed/instagram-feed.php',
		'instagramFeedPro'     => 'instagram-feed-pro/instagram-feed.php',
		'facebookFeed'         => 'custom-facebook-feed/custom-facebook-feed.php',
		'facebookFeedPro'      => 'custom-facebook-feed-pro/custom-facebook-feed.php',
		'twitterFeed'          => 'custom-twitter-feeds/custom-twitter-feed.php',
		'twitterFeedPro'       => 'custom-twitter-feeds-pro/custom-twitter-feed.php',
		'youTubeFeed'          => 'feeds-for-youtube/youtube-feed.php',
		'youTubeFeedPro'       => 'youtube-feed-pro/youtube-feed.php',
		'pushEngage'           => 'pushengage/main.php',
		'sugarCalendar'        => 'sugar-calendar-lite/sugar-calendar-lite.php',
		'sugarCalendarPro'     => 'sugar-calendar/sugar-calendar.php',
		'wpSimplePay'          => 'stripe/stripe-checkout.php',
		'wpSimplePayPro'       => 'wp-simple-pay-pro-3/simple-pay.php',
		'easyDigitalDownloads' => 'easy-digital-downloads/easy-digital-downloads.php',
		'searchWp'             => 'searchwp/index.php',
		'affiliateWp'          => 'affiliate-wp/affiliate-wp.php'
	];

	/**
	 * An array of links for admin settings.
	 *
	 * @since 4.0.0
	 *
	 * @var array
	 */
	public $pluginAdminUrls = [
		'optinMonster'         => 'admin.php?page=optin-monster-api-settings',
		'wpForms'              => 'admin.php?page=wpforms-settings',
		'wpFormsPro'           => 'admin.php?page=wpforms-settings',
		'miLite'               => 'admin.php?page=monsterinsights_settings#/',
		'miPro'                => 'admin.php?page=monsterinsights_settings#/',
		'emLite'               => 'admin.php?page=exactmetrics_settings#/',
		'emPro'                => 'admin.php?page=exactmetrics_settings#/',
		'wpMail'               => 'admin.php?page=wp-mail-smtp',
		'wpMailPro'            => 'admin.php?page=wp-mail-smtp',
		'seedProd'             => 'admin.php?page=seed_csp4',
		'seedProdPro'          => 'admin.php?page=seed_csp4',
		'rafflePress'          => 'admin.php?page=rafflepress_lite#/settings',
		'rafflePressPro'       => 'admin.php?page=rafflepress_lite#/settings',
		'trustPulse'           => 'admin.php?page=trustpulse',
		'instagramFeed'        => 'admin.php?page=sb-instagram-feed',
		'instagramFeedPro'     => 'admin.php?page=sb-instagram-feed',
		'facebookFeed'         => 'admin.php?page=cff-top',
		'facebookFeedPro'      => 'admin.php?page=cff-top',
		'twitterFeed'          => 'admin.php?page=custom-twitter-feeds',
		'twitterFeedPro'       => 'admin.php?page=custom-twitter-feeds',
		'youTubeFeed'          => 'admin.php?page=youtube-feed',
		'youTubeFeedPro'       => 'admin.php?page=youtube-feed',
		'pushEngage'           => 'admin.php?page=pushengage-admin',
		'sugarCalendar'        => 'admin.php?page=sugar-calendar',
		'sugarCalendarPro'     => 'admin.php?page=sugar-calendar',
		'wpSimplePay'          => 'edit.php?post_type=simple-pay',
		'wpSimplePayPro'       => 'edit.php?post_type=simple-pay',
		'easyDigitalDownloads' => 'edit.php?post_type=download',
		'searchWp'             => 'options-general.php?page=searchwp',
		'affiliateWp'          => 'admin.php?page=affiliate-wp'
	];

	/**
	 * Run an upgrade/installation.
	 *
	 * Attempt to download the package (if it is not a local file), unpack it, and
	 * install it in the destination folder.
	 *
	 * @since 1.5.6.1
	 *
	 * @param array $options {
	 *     Array or string of arguments for upgrading/installing a package.
	 *
	 *     @type string $package                     The full path or URI of the package to install.
	 *                                               Default empty.
	 *     @type string $destination                 The full path to the destination folder.
	 *                                               Default empty.
	 *     @type bool   $clear_destination           Whether to delete any files already in the
	 *                                               destination folder. Default false.
	 *     @type bool   $clear_working               Whether to delete the files form the working
	 *                                               directory after copying to the destination.
	 *                                               Default false.
	 *     @type bool   $abort_if_destination_exists Whether to abort the installation if the destination
	 *                                               folder already exists. When true, `$clear_destination`
	 *                                               should be false. Default true.
	 *     @type bool   $is_multi                    Whether this run is one of multiple upgrade/installation
	 *                                               actions being performed in bulk. When true, the skin
	 *                                               WP_Upgrader::header() and WP_Upgrader::footer()
	 *                                               aren't called. Default false.
	 *     @type array  $hook_extra                  Extra arguments to pass to the filter hooks called by
	 *                                               WP_Upgrader::run().
	 * }
	 * @return array|false|WP_error The result from self::install_package() on success, otherwise a WP_Error,
	 *                              or false if unable to connect to the filesystem.
	 */
	public function run( $options ) {

		$defaults = [
			'package'                     => '', // Please always pass this.
			'destination'                 => '', // And this
			'clear_destination'           => false,
			'abort_if_destination_exists' => true, // Abort if the Destination directory exists, Pass clear_destination as false please
			'clear_working'               => true,
			'is_multi'                    => false,
			'hook_extra'                  => [], // Pass any extra $hook_extra args here, this will be passed to any hooked filters.
		];

		$options = wp_parse_args( $options, $defaults );

		/**
		 * Filter the package options before running an update.
		 *
		 * See also {@see 'upgrader_process_complete'}.
		 *
		 * @since 4.3.0
		 *
		 * @param array $options {
		 *     Options used by the upgrader.
		 *
		 *     @type string $package                     Package for update.
		 *     @type string $destination                 Update location.
		 *     @type bool   $clear_destination           Clear the destination resource.
		 *     @type bool   $clear_working               Clear the working resource.
		 *     @type bool   $abort_if_destination_exists Abort if the Destination directory exists.
		 *     @type bool   $is_multi                    Whether the upgrader is running multiple times.
		 *     @type array  $hook_extra {
		 *         Extra hook arguments.
		 *
		 *         @type string $action               Type of action. Default 'update'.
		 *         @type string $type                 Type of update process. Accepts 'plugin', 'theme', or 'core'.
		 *         @type bool   $bulk                 Whether the update process is a bulk update. Default true.
		 *         @type string $plugin               Path to the plugin file relative to the plugins directory.
		 *         @type string $theme                The stylesheet or template name of the theme.
		 *         @type string $language_update_type The language pack update type. Accepts 'plugin', 'theme',
		 *                                            or 'core'.
		 *         @type object $language_update      The language pack update offer.
		 *     }
		 * }
		 */
		$options = apply_filters( 'upgrader_package_options', $options );

		if ( ! $options['is_multi'] ) { // call $this->header separately if running multiple times
			$this->skin->header();
		}

		// Connect to the Filesystem first.
		$res = $this->fs_connect( [ WP_CONTENT_DIR, $options['destination'] ] );
		// Mainly for non-connected filesystem.
		if ( ! $res ) {
			if ( ! $options['is_multi'] ) {
				$this->skin->footer();
			}

			return false;
		}

		$this->skin->before();

		if ( is_wp_error( $res ) ) {
			$this->skin->error( $res );
			$this->skin->after();
			if ( ! $options['is_multi'] ) {
				$this->skin->footer();
			}

			return $res;
		}

		/*
		 * Download the package (Note, This just returns the filename
		 * of the file if the package is a local file)
		 */
		$download = $this->download_package( $options['package'], true );

		// Allow for signature soft-fail.
		// WARNING: This may be removed in the future.
		if ( is_wp_error( $download ) && $download->get_error_data( 'softfail-filename' ) ) {

			// Don't output the 'no signature could be found' failure message for now.
			if ( 'signature_verification_no_signature' !== $download->get_error_code() || WP_DEBUG ) {
				// Outout the failure error as a normal feedback, and not as an error:
				//$this->skin->feedback( $download->get_error_message() );

				// Report this failure back to WordPress.org for debugging purposes.
				wp_version_check(
					[
						'signature_failure_code' => $download->get_error_code(),
						'signature_failure_data' => $download->get_error_data(),
					]
				);
			}

			// Pretend this error didn't happen.
			$download = $download->get_error_data( 'softfail-filename' );
		}

		if ( is_wp_error( $download ) ) {
			$this->skin->error( $download );
			$this->skin->after();
			if ( ! $options['is_multi'] ) {
				$this->skin->footer();
			}

			return $download;
		}

		$delete_package = ( $download !== $options['package'] ); // Do not delete a "local" file

		// Unzips the file into a temporary directory.
		$working_dir = $this->unpack_package( $download, $delete_package );
		if ( is_wp_error( $working_dir ) ) {
			$this->skin->error( $working_dir );
			$this->skin->after();
			if ( ! $options['is_multi'] ) {
				$this->skin->footer();
			}

			return $working_dir;
		}

		// With the given options, this installs it to the destination directory.
		$result = $this->install_package(
			[
				'source'                      => $working_dir,
				'destination'                 => $options['destination'],
				'clear_destination'           => $options['clear_destination'],
				'abort_if_destination_exists' => $options['abort_if_destination_exists'],
				'clear_working'               => $options['clear_working'],
				'hook_extra'                  => $options['hook_extra'],
			]
		);

		$this->skin->set_result( $result );
		if ( is_wp_error( $result ) ) {
			$this->skin->error( $result );
			//$this->skin->feedback( 'process_failed' );
		} else {
			// Installation succeeded.
			//$this->skin->feedback( 'process_success' );
		}

		$this->skin->after();

		if ( ! $options['is_multi'] ) {

			/**
			 * Fire when the upgrader process is complete.
			 *
			 * See also {@see 'upgrader_package_options'}.
			 *
			 * @since 3.6.0
			 * @since 3.7.0 Added to WP_Upgrader::run().
			 * @since 4.6.0 `$translations` was added as a possible argument to `$hook_extra`.
			 *
			 * @param WP_Upgrader $this WP_Upgrader instance. In other contexts, $this, might be a
			 *                          Theme_Upgrader, Plugin_Upgrader, Core_Upgrade, or Language_Pack_Upgrader instance.
			 * @param array       $hook_extra {
			 *     Array of bulk item update data.
			 *
			 *     @type string $action       Type of action. Default 'update'.
			 *     @type string $type         Type of update process. Accepts 'plugin', 'theme', 'translation', or 'core'.
			 *     @type bool   $bulk         Whether the update process is a bulk update. Default true.
			 *     @type array  $plugins      Array of the basename paths of the plugins' main files.
			 *     @type array  $themes       The theme slugs.
			 *     @type array  $translations {
			 *         Array of translations update data.
			 *
			 *         @type string $language The locale the translation is for.
			 *         @type string $type     Type of translation. Accepts 'plugin', 'theme', or 'core'.
			 *         @type string $slug     Text domain the translation is for. The slug of a theme/plugin or
			 *                                'default' for core translations.
			 *         @type string $version  The version of a theme, plugin, or core.
			 *     }
			 * }
			 */
			do_action( 'upgrader_process_complete', $this, $options['hook_extra'] );

			$this->skin->footer();
		}

		return $result;
	}

	/**
	 * Toggle maintenance mode for the site.
	 *
	 * Create/delete the maintenance file to enable/disable maintenance mode.
	 *
	 * @since 2.8.0
	 *
	 * @global WP_Filesystem_Base $wp_filesystem Subclass
	 *
	 * @param bool $enable True to enable maintenance mode, false to disable.
	 */
	public function maintenance_mode( $enable = false ) { // phpcs:ignore PSR1.Methods.CamelCapsMethodName.NotCamelCaps
		global $wp_filesystem;
		$file = $wp_filesystem->abspath() . '.maintenance';
		if ( $enable ) {
			//$this->skin->feedback( 'maintenance_start' );
			// Create maintenance file to signal that we are upgrading
			$maintenance_string = '<?php $upgrading = ' . time() . '; ?>';
			$wp_filesystem->delete( $file );
			$wp_filesystem->put_contents( $file, $maintenance_string, FS_CHMOD_FILE );
		} elseif ( ! $enable && $wp_filesystem->exists( $file ) ) {
			//$this->skin->feedback( 'maintenance_end' );
			$wp_filesystem->delete( $file );
		}
	}

	/**
	 * Download a package.
	 *
	 * @since 2.8.0
	 * @since 5.5.0 Added the `$hook_extra` parameter.
	 *
	 * @param string $package          The URI of the package. If this is the full path to an
	 *                                 existing local file, it will be returned untouched.
	 * @param bool   $check_signatures Whether to validate file signatures. Default false.
	 * @param array  $hook_extra       Extra arguments to pass to the filter hooks. Default empty array.
	 * @return string|WP_Error The full path to the downloaded package file, or a WP_Error object.
	 */
	public function download_package( $package, $check_signatures = false, $hook_extra = [] ) { // phpcs:ignore PSR1.Methods.CamelCapsMethodName.NotCamelCaps

		/**
		 * Filters whether to return the package.
		 *
		 * @since 3.7.0
		 * @since 5.5.0 Added the `$hook_extra` parameter.
		 *
		 * @param bool        $reply      Whether to bail without returning the package.
		 *                                Default false.
		 * @param string      $package    The package file name.
		 * @param WP_Upgrader $this       The WP_Upgrader instance.
		 * @param array       $hook_extra Extra arguments passed to hooked filters.
		 */
		$reply = apply_filters( 'upgrader_pre_download', false, $package, $this, $hook_extra );
		if ( false !== $reply ) {
			return $reply;
		}

		if ( ! preg_match( '!^(http|https|ftp)://!i', $package ) && file_exists( $package ) ) { // Local file or remote?
			return $package; // Must be a local file.
		}

		if ( empty( $package ) ) {
			return new WP_Error( 'no_package', $this->strings['no_package'] );
		}

		//$this->skin->feedback( 'downloading_package', $package );

		$download_file = download_url( $package, 300, $check_signatures );

		if ( is_wp_error( $download_file ) && ! $download_file->get_error_data( 'softfail-filename' ) ) {
			return new WP_Error( 'download_failed', $this->strings['download_failed'], $download_file->get_error_message() );
		}

		return $download_file;
	}

	/**
	 * Unpack a compressed package file.
	 *
	 * @since 2.8.0
	 *
	 * @global WP_Filesystem_Base $wp_filesystem WordPress filesystem subclass.
	 *
	 * @param string $package        Full path to the package file.
	 * @param bool   $delete_package Optional. Whether to delete the package file after attempting
	 *                               to unpack it. Default true.
	 * @return string|WP_Error The path to the unpacked contents, or a WP_Error on failure.
	 */
	public function unpack_package( $package, $delete_package = true ) { // phpcs:ignore PSR1.Methods.CamelCapsMethodName.NotCamelCaps
		global $wp_filesystem;

		//$this->skin->feedback( 'unpack_package' );

		$upgrade_folder = $wp_filesystem->wp_content_dir() . 'upgrade/';

		//Clean up contents of upgrade directory beforehand.
		$upgrade_files = $wp_filesystem->dirlist( $upgrade_folder );
		if ( ! empty( $upgrade_files ) ) {
			foreach ( $upgrade_files as $file ) {
				$wp_filesystem->delete( $upgrade_folder . $file['name'], true );
			}
		}

		// We need a working directory - Strip off any .tmp or .zip suffixes
		$working_dir = $upgrade_folder . basename( basename( $package, '.tmp' ), '.zip' );

		// Clean up working directory
		if ( $wp_filesystem->is_dir( $working_dir ) ) {
			$wp_filesystem->delete( $working_dir, true );
		}

		// Unzip package to working directory
		$result = unzip_file( $package, $working_dir );

		// Once extracted, delete the package if required.
		if ( $delete_package ) {
			unlink( $package );
		}

		if ( is_wp_error( $result ) ) {
			$wp_filesystem->delete( $working_dir, true );
			if ( 'incompatible_archive' === $result->get_error_code() ) {
				return new WP_Error( 'incompatible_archive', $this->strings['incompatible_archive'], $result->get_error_data() );
			}

			return $result;
		}

		return $working_dir;
	}

	/**
	 * Install a package.
	 *
	 * Copies the contents of a package form a source directory, and installs them in
	 * a destination directory. Optionally removes the source. It can also optionally
	 * clear out the destination folder if it already exists.
	 *
	 * @since 2.8.0
	 *
	 * @global WP_Filesystem_Base $wp_filesystem        WordPress filesystem subclass.
	 * @global array              $wp_theme_directories
	 *
	 * @param array|string $args {
	 *     Optional. Array or string of arguments for installing a package. Default empty array.
	 *
	 *     @type string $source                      Required path to the package source. Default empty.
	 *     @type string $destination                 Required path to a folder to install the package in.
	 *                                               Default empty.
	 *     @type bool   $clear_destination           Whether to delete any files already in the destination
	 *                                               folder. Default false.
	 *     @type bool   $clear_working               Whether to delete the files form the working directory
	 *                                               after copying to the destination. Default false.
	 *     @type bool   $abort_if_destination_exists Whether to abort the installation if
	 *                                               the destination folder already exists. Default true.
	 *     @type array  $hook_extra                  Extra arguments to pass to the filter hooks called by
	 *                                               WP_Upgrader::install_package(). Default empty array.
	 * }
	 *
	 * @return array|WP_Error The result (also stored in `WP_Upgrader::$result`), or a WP_Error on failure.
	 */
	public function install_package( $args = [] ) { // phpcs:ignore PSR1.Methods.CamelCapsMethodName.NotCamelCaps
		global $wp_filesystem, $wp_theme_directories;

		$defaults = [
			'source'                      => '', // Please always pass this
			'destination'                 => '', // and this
			'clear_destination'           => false,
			'clear_working'               => false,
			'abort_if_destination_exists' => true,
			'hook_extra'                  => [],
		];

		$args = wp_parse_args( $args, $defaults );

		// These were previously extract()'d.
		$source            = $args['source'];
		$destination       = $args['destination'];
		$clear_destination = $args['clear_destination'];

		set_time_limit( 300 );

		if ( empty( $source ) || empty( $destination ) ) {
			return new WP_Error( 'bad_request', $this->strings['bad_request'] );
		}
		//$this->skin->feedback( 'installing_package' );

		/**
		 * Filter the install response before the installation has started.
		 *
		 * Returning a truthy value, or one that could be evaluated as a WP_Error
		 * will effectively short-circuit the installation, returning that value
		 * instead.
		 *
		 * @since 2.8.0
		 *
		 * @param bool|WP_Error $response   Response.
		 * @param array         $hook_extra Extra arguments passed to hooked filters.
		 */
		$res = apply_filters( 'upgrader_pre_install', true, $args['hook_extra'] );

		if ( is_wp_error( $res ) ) {
			return $res;
		}

		//Retain the Original source and destinations
		$remote_source     = $args['source'];
		$local_destination = $destination;

		$source_files       = array_keys( $wp_filesystem->dirlist( $remote_source ) );
		$remote_destination = $wp_filesystem->find_folder( $local_destination );

		//Locate which directory to copy to the new folder, This is based on the actual folder holding the files.
		if ( 1 === count( $source_files ) && $wp_filesystem->is_dir( trailingslashit( $args['source'] ) . $source_files[0] . '/' ) ) { //Only one folder? Then we want its contents.
			$source = trailingslashit( $args['source'] ) . trailingslashit( $source_files[0] );
		} elseif ( count( $source_files ) === 0 ) {
			return new WP_Error( 'incompatible_archive_empty', $this->strings['incompatible_archive'], $this->strings['no_files'] ); // There are no files?
		} else { // It's only a single file, the upgrader will use the folder name of this file as the destination folder. Folder name is based on zip filename.
			$source = trailingslashit( $args['source'] );
		}

		/**
		 * Filter the source file location for the upgrade package.
		 *
		 * @since 2.8.0
		 * @since 4.4.0 The $hook_extra parameter became available.
		 *
		 * @param string      $source        File source location.
		 * @param string      $remote_source Remote file source location.
		 * @param WP_Upgrader $this          WP_Upgrader instance.
		 * @param array       $hook_extra    Extra arguments passed to hooked filters.
		 */
		$source = apply_filters( 'upgrader_source_selection', $source, $remote_source, $this, $args['hook_extra'] );

		if ( is_wp_error( $source ) ) {
			return $source;
		}

		// Has the source location changed? If so, we need a new source_files list.
		if ( $source !== $remote_source ) {
			$source_files = array_keys( $wp_filesystem->dirlist( $source ) );
		}

		/*
		 * Protection against deleting files in any important base directories.
		 * Theme_Upgrader & Plugin_Upgrader also trigger this, as they pass the
		 * destination directory (WP_PLUGIN_DIR / wp-content/themes) intending
		 * to copy the directory into the directory, whilst they pass the source
		 * as the actual files to copy.
		 */
		$protected_directories = [ ABSPATH, WP_CONTENT_DIR, WP_PLUGIN_DIR, WP_CONTENT_DIR . '/themes' ];

		if ( is_array( $wp_theme_directories ) ) {
			$protected_directories = array_merge( $protected_directories, $wp_theme_directories );
		}

		if ( in_array( $destination, $protected_directories, true ) ) {
			$remote_destination = trailingslashit( $remote_destination ) . trailingslashit( basename( $source ) );
			$destination        = trailingslashit( $destination ) . trailingslashit( basename( $source ) );
		}

		if ( $clear_destination ) {
			// We're going to clear the destination if there's something there.
			//$this->skin->feedback( 'remove_old' );

			$removed = $this->clear_destination( $remote_destination );

			/**
			 * Filter whether the upgrader cleared the destination.
			 *
			 * @since 2.8.0
			 *
			 * @param mixed  $removed            Whether the destination was cleared. true on success, WP_Error on failure
			 * @param string $local_destination  The local package destination.
			 * @param string $remote_destination The remote package destination.
			 * @param array  $hook_extra         Extra arguments passed to hooked filters.
			 */
			$removed = apply_filters( 'upgrader_clear_destination', $removed, $local_destination, $remote_destination, $args['hook_extra'] );

			if ( is_wp_error( $removed ) ) {
				return $removed;
			}
		} elseif ( $args['abort_if_destination_exists'] && $wp_filesystem->exists( $remote_destination ) ) {
			//If we're not clearing the destination folder and something exists there already, Bail.
			//But first check to see if there are actually any files in the folder.
			$_files = $wp_filesystem->dirlist( $remote_destination );
			if ( ! empty( $_files ) ) {
				$wp_filesystem->delete( $remote_source, true ); //Clear out the source files.

				return new WP_Error( 'folder_exists', $this->strings['folder_exists'], $remote_destination );
			}
		}

		//Create destination if needed
		if ( ! $wp_filesystem->exists( $remote_destination ) ) {
			if ( ! $wp_filesystem->mkdir( $remote_destination, FS_CHMOD_DIR ) ) {
				return new WP_Error( 'mkdir_failed_destination', $this->strings['mkdir_failed'], $remote_destination );
			}
		}
		// Copy new version of item into place.
		$result = copy_dir( $source, $remote_destination );
		if ( is_wp_error( $result ) ) {
			if ( $args['clear_working'] ) {
				$wp_filesystem->delete( $remote_source, true );
			}

			return $result;
		}

		//Clear the Working folder?
		if ( $args['clear_working'] ) {
			$wp_filesystem->delete( $remote_source, true );
		}

		$destination_name = basename( str_replace( $local_destination, '', $destination ) );
		if ( '.' === $destination_name ) {
			$destination_name = '';
		}

		$this->result = compact( 'source', 'source_files', 'destination', 'destination_name', 'local_destination', 'remote_destination', 'clear_destination' );

		/**
		 * Filter the installation response after the installation has finished.
		 *
		 * @since 2.8.0
		 *
		 * @param bool  $response   Installation response.
		 * @param array $hook_extra Extra arguments passed to hooked filters.
		 * @param array $result     Installation result data.
		 */
		$res = apply_filters( 'upgrader_post_install', true, $args['hook_extra'], $this->result );

		if ( is_wp_error( $res ) ) {
			$this->result = $res;

			return $res;
		}

		//Bombard the calling function will all the info which we've just used.
		return $this->result;
	}
}